To their _______, they all passed the exam.
| A．surprise | B．surprised | C．surprising | D．surprises |
17．—Is there any better way to help my son get rid of the habit of playing computer games?
—To tell you the truth, it’s very hard. But we_______on this problem to improve the situation.
| A．were working | B．had worked | C．are working | D．had been working |
16．—Where is Lily, Lucy? I cannot find her anywhere.
—She_________have been off long. I saw her clean the window just now.
| A．shouldn’t | B．can’t | C．mustn’t | D．needn’t |
15．While he has failed again and again, he never gives up in order to________his dream.
| A．achieve | B．awake | C．admit | D．Control |
14．This doubt had been in my mind for some time, but the research still went on____some reasons.
| A．to | B．about | C．for | D．In |
13．Not until I was a senior student_________the importance of English.
| A．I have realized | B．did I realize | C．have I realized | D．I realized |